As bourbon boomed over the past two decades, one of the most famous distillers stuck to its knitting: Maker’s Mark. Since the fifties, Maker’s had staked its reputation on just one bourbon from its facility in Loretto, Kentucky: the smooth, sweet whiskey in the wax-topped bottles.

Everything changes this summer with the release of Maker’s 46, the company’s answer to the vogue for small-production, more intense bourbons. Basically, says master distiller Kevin Smith, Maker's is responding to the “whiskey geeks” who pound the bars for new products and “bigger, bolder” bourbons. In other words, the guy who guards Maker’s main moneymaker—its unchanging, smooth flavor profile—is leading a charge into new territory. Modest as the charge is (46 will be a drop in Maker’s big bucket), Kevin is as excited and nervous as a new father.

I tasted 46 in March, and it IS a bit bigger and bolder. As Kevin says, “It’s sharper, it’s pointier, it’s edgier, it’s not as round.” The whiskey geeks will probably describe more rye-like spice, less sweetness, and a bit of bite, though nothing like the intensity of, say, Booker’s. If “pointier” bourbon sounds like heresy to the folks who cherish Maker’s for its very roundness and smoothness, Kevin is eager to see the market vote.

In any case, there’s a lot of Maker’s DNA in the new bottle. 46 is not a whole new whiskey: Think of it as Maker’s Plus. It’s made by taking original Maker’s—which has spent about 5 1/2 years in toasted oak barrels—and aging it an additional 2 to 3 months in used barrels in which 10 new oak staves have been suspended. These pieces of oak have been cooked according to a special “recipe” that was developed by Kevin’s collaborators at the Independent Stave barrel company.

A brief bath in new oak may seem like cheating to the fans of, say, 18-year-old single-barrel bourbons, but if nothing else 46 is a lesson in what wood lends to whiskey. Kevin says the delicate way the new wood is heated produces unique notes; it is not charred black (which adds a lot of sweetness and vanilla flavors to barrels, when the sugars in the wood caramelize) but, rather, lightly “seared.” A lot of research by Missouri-based barrel maker Independent Stave went into developing this new heating formula—called, as you may have guessed, formula 46.

The bottle is new, too: tapered, elegant, still with the wax cap. The price is about $10 higher than regular Maker’s. Distribution is national.